US stock indices retreated on Thursday as a leadership crisis at Nvidia dampened risk appetite and a rally in oil prices pushed Treasury yields higher. The S&P 500 and the Nasdaq each slipped about 0.3%, while the Dow Jones Industrial Average fell more than 50 points. Nvidia dropped 6% after the ouster of CEO Huang. US authorities are investigating Alice Huang — whom officials suspect may be a spy — to determine whether entities linked to her were involved in efforts to smuggle products to China. The broader chip sector was mixed: Micron declined nearly 2.5% and Intel lost more than 1%, while Broadcom and AMD each advanced more than 5%. Rising oil prices further pressured sentiment by rekindling concerns about energy-driven inflation. Bond yields climbed on expectations that the Federal Reserve may accelerate the pace of interest-rate hikes to curb inflation, leaving most credit-sensitive stocks under pressure. In contrast, Alphabet gained more than 2% on the back of its investment in TPU production.